Nitro-aryl amino-aryl amines



Patented July 2, 1935 UNITED STATES 2,006,735 NITRO-ARYL AMINO-ARYL AMINES Erich Fischer, Bad 'Soden-on-the-Taunus, and

Emil Mahler, Franktfo Y., a corporation of Dela- Gcrmany, assignors Inc., New York, N. ware No Drawing.

rt-on-the-Main-Hochst,

General Aniline Works,

Application November 7, 1933,

-Serial No. 697,081. In Germany November 1'7,

Claims.

The present invention relates to new nitroarylfamino-aryl amines which are valuable dyestufis, more particularly it relates to new dyestuffs of the general formula:

n n-u-m-nn-Qm NO: 7 wherein R and R1 represent radicals of the benzene series or R means a cyclohexyl radical and R1 a radical of the benzene series, the N H- groups standing in-parapositions to each other, and R2 stands for a radical of the group consisting of 7 COOH, COO-metaLCOO-alkyl-and ooN wherein X means hydrogen and X1 hydrogen, alkyl, phenyl or cyclohexyl, or X and X1 represent alkyl radicals.

Our new dyestuffs are obtainable by condensing para-aminodiphenylamine, including its homologues, substitution and hydrogenation products, --with -'a 4-halogen-3-nitro-l-benzoic acid or benzoic acid compound of the general formula:

lhalogen formula:

acyl

and then splitting oh the acyl group from the 5:, condensation products. The condensation reaction is carried out by heating in an open vessel or under pressure or in a stream of nitrogen.

The new dyestuffs dye, so far as they contain a sulfonic acid'group, the animal fiber brown tints of good fastness properties. The non-sulfonated dyes are suitable for dyeing cellulose esters and ethers. It is remarkable and very surprising that the new dyestuffs above identified are superior I with regard to their fastness to light to those dyestuffs which are obtainable, for instance, from 4-halogen-3.5-dinitro-1-benz0ic acid.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, the parts being by weight:

(1) 201.5 parts of 4-chloro-3-nitro-l-benzenecarboxylic acid are dissolved in water by adding sodium carbonate to form the sodium salt; 184- parts of paraamino-diphenylamine and an excess'of chalkare added thereto. "The mixture is heated to boiling, while stirring until the condensation is finished. The-whole is filtered by suction, the residue is extracted by boiling with dilute hydrochloric acid, and the reaction product is crystallized from water in the form of its sodium salt. The sodium salt forms a product which is soluble in; hot water. The dyestuff dyes acetate silk brown tints of good fastness to light. It has the following formula:

GHQ-NEG formula:

SOaH NO:

Dyestuffs of similar properties are obtainable by replacing 4-chloro-3-nitro-l-benzoic acid by, for instance, 4-chloro-3-nitro-1-benzolc acid: ethyl-ester, -methyles ter, -propylester or 4- chloro-3-nitro-1-benzoic acid-amide. Instead of OOOH the latter there may also be used other amides such as, for instance, 4-chloro-3-nitro-l-benzoic acid-methylamide, -ethylamide, -phenylamide, -cyclohexylamide, -dimethylamide, -diethylamide or other compounds which are analogous to those in the specific examples.

Instead of the 4-amino-diphenylamine-2-sulfonic acid analogous compounds may be used, for instance, 4-amino-4'-methoxy-diphenylamine-2-sulfonic acid or l-amino-4-cyclohexylamino-3-sulfonic acid or 4-amino-4'-acetamino-di phenylamine-2-sulfonic acid.

(3) 268 parts of 4-amino-4' methyl-diphenylamine are dissolved in water, while adding 40 parts of magnesium oxide, and 246 parts of 4- bromo-B-nitro-l-benzoic acid are then added. Thereupon, a further quantity of 60 parts of magnesium oxide is introduced into the mixture and the whole is heated to boiling until the reaction is finished. The reaction product is precipitated by means of acid, filtered by suction and washed with water. The dyestuil' is then dissolved in hotwater and salted out by means of common salt. The dyestufi corresponds to the following formula:

7 r No.

- We claim: 1

l. The compounds of the .NO: wherein R and R1 represent radicals of the benzene series or R means a. cyclohexyl radical and R1 a radical of the benzene series the NH- groups standing 7 in I para-positions "to each other, and R2 stands for a radical of the group consisting 'of COOH, COO-metal, COO-alkyl and following general wherein X means hydrogen and X1 hydrogen,

alkyl, phenyl or cyclohexyl, or X and X1 represent alkyl radicals.

2. The compounds formula;

of the following general dyeing acetate silk brown tints of good fastness to light, bein soluble in the' form'of the alkali metal salt in hot water.

4. The compound of the formulas" being when isolated in the form r the sodium I SOaH water and dyeing wool from an acid bath eve:

red-brown tints.

salt a red-brown powder, easily soluble in'warIR 5. The compound of the formula:

CH3COHN NHNHOCOOH soar j N01 being when isolated in the form of the sodium salt a red-brown powder, easily soluble in warm water and dyeing wool from an acid 'bath even redbrown tints. g

' ERICH FISCHER.

EMIL MAHLERi 

